What is the reason some lipos have two taps? E-flites and electriflys have large wires to connect to the esc and small wires to connect to the charger, I've never seen an explanation for the charge discharge taps, also how does one determine the what amperage to set the charger for any given battery size? Sorry for all the newby questions.:o

ifixairplanes

10-16-2005, 12:49 AM

http://www.wattflyer.com/forums/showthread.php?t=863

Everything you need to know

hoppy

10-16-2005, 01:45 AM

One tap lead goes to each 'inner cell' connection. Some also run a tap to the + and - output terminals.

For a 2 cell pack, you would have one 'inner cell connection" and the two terminal leads = 3.

For a 3 cell pack, there would be 2 inner cell connections and the 2 terminals for a total of 4.

With these 'inner cell connections wires, you can measure the voltage of each cell and charge each cell individually.

They are there because it is important to keep LiPo cells within +/-0.03V of each other. If the individual cell voltages get too far apart, the cells can be permanently damaged (or even puff or ignite).

fabricator

10-16-2005, 01:48 AM

Thanks for the link and the replys guys.:)

JLK

10-24-2005, 11:50 PM

The mailman just delivered my order from Balsa Supply and it is after hours there now.
I plan to call tomorrow and get full instructions but my curiousity is killing me. On the Apache 3 cell LiPo packs I got from them there are two jacks:
1 is a two lead black and read. I assume this is for the ESC and charger.
Another is a 4 wire jack. Is this for charging thru a balancer and is not used otherwise?
Thanks!
JLK

ifixairplanes

10-25-2005, 12:48 AM

That is correct. On my lipo I have a balancer/charge guard that I always charge through. It keeps the cells balanced and prevents over charging.

Sean

JLK

10-25-2005, 12:56 AM

Sean,
So if I understand correctly you do not use the 2 wire plug that goes to the ESC to charge. You use the other connector, in my case a 3 cell LiPo, a 4 wire.
What type of charger do you use?
I just got a Hobbico 2 output.
I may use it tonight if I feel safe that I understand what I'm doing...charge thru the same 2 wire connector that will plug in to the ESC.
JLK

Unbalanced prop

10-27-2005, 01:57 PM

That is correct. On my lipo I have a balancer/charge guard that I always charge through. It keeps the cells balanced and prevents over charging.

Sean

Sean.........What "balancer/charger" guard are you using? Didn't know anyone made one yet.:confused: I know PQ has a PCM charge guard that will shut down a charge if the voltage for any cell gets too high, and TP, Hyperion and Astroflight make balancers. The Kokam Skyvolt system may be a balancer/charge guard, but I am not sure.

Doug

ifixairplanes

10-28-2005, 02:46 AM

I get my lipoly packs and the guard from 2dogrc.com
The device is made for his 3s packs, i imagine it will work with other 3s packs. But it monitors each cell's voltage individually and it shuts off the charge to a cell once it reaches max charge. The other cells still charge until they all shutoff. An hour after charging my cells are all within .03V or less of each other. Works good. I use that everytime I charge.

Sean

ifixairplanes

10-28-2005, 02:49 AM

Sean,
So if I understand correctly you do not use the 2 wire plug that goes to the ESC to charge. You use the other connector, in my case a 3 cell LiPo, a 4 wire.
What type of charger do you use?
I just got a Hobbico 2 output.
I may use it tonight if I feel safe that I understand what I'm doing...charge thru the same 2 wire connector that will plug in to the ESC.
JLK

Yes I only charge through the balancer. Mainly because the charger I bought (search: "polycharge" on tower) has a BEC connector on it from the factory. So did the charge guard, so instead of changing plugs I only use the guard. You can charge through the main leads though. But after many charges the cells may become unbalanced. The charge guard prevents that from happening and also prevents an unbalanced situation. It also keeps the pack from overcharging also. Great little device for $25.

Sean

qban_flyer

10-28-2005, 11:25 AM

What is the reason some lipos have two taps? E-flites and electriflys have large wires to connect to the esc and small wires to connect to the charger, I've never seen an explanation for the charge discharge taps, also how does one determine the what amperage to set the charger for any given battery size? Sorry for all the newby questions.:o

Electrifly packs are claimed to have (by G/P) a "charge protection circuit module board" to prevent the packs from damage while they are being charged.

I doubt this is like the "balancers" some others have since the Electrufly packs only carry two conductors in their charging cable regardless of how many cells there are in a pack. Other brands have three or more conductors, depending on the amount of cells in the pack.

Unbalanced prop

10-28-2005, 02:02 PM

I get my lipoly packs and the guard from 2dogrc.com
The device is made for his 3s packs, i imagine it will work with other 3s packs. But it monitors each cell's voltage individually and it shuts off the charge to a cell once it reaches max charge. The other cells still charge until they all shutoff. An hour after charging my cells are all within .03V or less of each other. Works good. I use that everytime I charge.

Sean

Thanks for the info Sean. I hadn't heard of this guard\balancer before. I would like the balance to be a little closer then .03v but that still is pretty good, and the price is ecellent! Can anyone else comment on this unit?